CO2-mediated thermal treatment of disposable plastic food containers

In accordance with global economic prosperity, the frequencies of food delivery and takeout orders have been increasing. The pandemic life, specifically arising from COVID-19, rapidly expanded the food delivery service. Thus, the massive generation of disposable plastic food containers has become significant environmental problems. Establishing a sustainable disposal platform for plastic packaging waste (PPW) of food delivery containers has intrigued particular interest. To comprise this grand challenge, a reliable thermal disposable platform has been suggested in this study. From the pyrolysis process, a heterogeneous plastic mixture of PPW was converted into syngas and value-added hydrocarbons (HCs). PPW collected from five different restaurants consisted of polypropylene (36.9 wt%), polyethylene (10.5 wt%), polyethylene terephthalate (18.1 wt%), polystyrene (13.5 wt%), polyvinyl chloride (4.2 wt%), and other composites (16.8 wt%). Due to these compositional complexities, pyrolysis of PPW led to formations of a variety of benzene derivatives and aliphatic HCs. Adapting multi-stage pyrolysis, the different chemicals were converted into industrial chemicals (benzene, toluene, styrene, etc.). To selectively convert HCs into syngas (H2 and CO), catalytic pyrolysis was adapted using supported Ni catalyst (5 wt% Ni/SiO2). Over Ni catalyst, H2 was produced as a main product due to C[sbnd]H bond scission of HCs. When CO2 was used as a co-reactant, HCs were further transformed to H2 and CO through the chemical reactions of CO2 with gas phase HCs. CO2-assisted catalytic pyrolysis also retarded catalyst deactivation inhibiting coke deposition on Ni catalyst. © 2022 Elsevier B.V.

Pre-clinical safety evaluation for mRNA-vaccine development in mouse model

Messenger RNA (mRNA) vaccine has emerged as an attractive agent for prevention of infectious disease and anti-cancer therapy. However, there is a fatal risk that the safety evaluation for mRNA vaccine have not been fully studied yet. In this study, we evaluated the safety of four type of COVID-19 S-protein targeting mRNA vaccines with different compositions (C2/ LNP90, C2LNP128, C3LNP90 and C3LNP128). Theses vaccines were intramuscularly injected to 6-wk old male and female ICR mice with twice at an interval of 2 wks. The necropsy was carried out on 2 days or 14 days after secondary injection. The results showed that the body weight was decreased for 2days after the first injection in C2/LNP128 and C3/LNP128-injected mice, but it was almost recovered at 7day post injection (dpi). At 2 dpi after secondary injection, the endpoint blood analysis of demonstrated that C2/LNP128 and C3/LNP128 decreased the number of lymphocytes, monocytes and reticulocytes carrying the abnormal level of liver function indicator such as albumin, AST, ALT and total protein. Additionally, C2/LNP128 decreased the number of platelet and C3LNP128 decreased the number of red blood cells, respectably. Spleen and inguinal lymph node were enlarged in all experimental group. Notably, C2/LNP128 and C3/LNP128 induced severe edema in injection site, femoris muscle. At 14 dpi after secondary injection, the toxicity that was observed at 2 dpi after secondary injection was recovered. These results suggest that the potential side effects of mRNA vaccines must be systematically evaluated with multiple aspect of toxicology.

Establishment of a Mouse Model to Evaluate mRNA Vaccine Safety

FDA granted emergency use authorization (EUA) for the world's first mRNA vaccine, developed by Pfizer-BioNTech, in December 2020. As a result, many vaccinated people were protected from the fatality of COVID-19, but some people suffered from various side effects of the mRNA vaccine. The EUA was immediately decided to control COVID-19 pandemic and the deregulation of preclinical safety assessment for mRNA vaccine was inevitable. In preclinical phase, efficacy assessment of several mRNA vaccine candidates has been performed by using COVID-19 mouse infection model. However, the guideline of safety assessment for mRNA vaccine in mice has not yet been established. Therefore, it is necessary to identify mRNA vaccineinduced toxicity and clinical symptoms. In this study, we evaluated the clinical and serologic changes induced by the intramuscular injection of 4 types of mRNA vaccines (100 mug/head) with different compositions (C2/LNP90, C2LNP128, C3LNP90, and C3LNP128) in 6-wk-old male and female ICR mice. Five mice per group, a total of 25 male and female mice, respectively, were used in this study. mRNA vaccines were injected twice at an interval of 2 wk and necropsy was carried out 2 d after secondary injection. CBC, blood chemistry analysis, and visual evaluation of whole-body tissues were performed. The results showed that the body weight was decreased for 2 d after the first injection in C2/LNP128 and C3/LNP128- injected mice compared to vehicle-injected mice, but it was almost recovered at 14 d postinjection (dpi). The endpoint blood and serum analysis demonstrated that C2/LNP128 and C3/LNP128 decreased the number of lymphocyte, monocyte, and reticulocyte carrying the abnormal level of liver function indicator such as albumin, AST, ALT, and total protein. Additionally, C2/LNP128 decreased the number of platelets and C3LNP128 decreased the number of red blood cells, respectively. Spleen and inguinal lymph nodes were enlarged in all experimental groups compared to the control group. Notably, C2/ LNP128 and C3/LNP128 induced severe edema in the injection site, the femoral muscle, that was significantly enlarged. Although more detailed analyses should be carried out, these results suggest that the safety assessment of mRNA vaccines must be systematically established with multiple aspects of toxicology and laboratory animal medicine.

JUE Insight: How do cities change when we work from home?

How would the shape of our cities change if there were a permanent increase in working from home? We study this question using a quantitative model of the Los Angeles metropolitan area featuring local agglomeration externalities and endogenous traffic congestion. We find three important effects: (1) Jobs move to the core of the city, while residents move to the periphery. (2) Traffic congestion eases and travel times drop. (3) Average real estate prices fall, with declines in core locations and increases in the periphery. Workers who are able to switch to telecommuting enjoy large welfare gains by saving commute time and moving to more affordable neighborhoods. Workers who continue to work on-site enjoy modest welfare gains due to lower commute times, improved access to jobs, and the fall in average real estate prices.

Status of Ambient PM2.5 Pollution in the Seoul Megacity (2020)

The Center for Air Quality &Control at the Seoul Research Institute of Public Health and the Environment (SIHE) has monitored changes in the concentration of fine dust in Seoul over the past 10 years and investigated meteorological factors as well as fine particulate matter (PM2.5), sulfur dioxide (SO2), and nitrogen dioxide (NO2) concentrations in northeastern China and its contribution to the PM2.5 concentration in Seoul. The concentration of fine dust in Seoul in 2020 was 21 µg/m3, which is down 16% from 2019 and the lowest since 2010. In 2020, China’s emissions of pollutants such as NO2 have decreased significantly due to regional blockades, social distancing, and factory shutdowns caused by COVID-19. As a results, the concentration of precursors such as SO2 and NO2, and PM2.5 in northeastern China are also decreased, which contributed to the reduction in PM2.5 concentration in Seoul caused by westerly winds blowing. In addition, the ratio of east and south winds that usually contain low concentrations of pollutants was more than 30% of the total air currents into Seoul, which is the highest in the last three years. Moreover, the mean wind velocity and the amount of precipitation were also the highest recorded values of 2.4 m/s and 1651.0 mm, respectively. Calculations using Comprehensive Air quality Model with eXtensions (CAMx)-Particulate Source Apportionment Technology (PSAT) show that the contribution of external inflows to the PM2.5 concentration in Seoul was 65%. We believe that the reasons for the low PM2.5 concentration in 2020 are due to meteorological factors and a decrease in air pollution in northeastern China. Meanwhile, the major contribution of emissions in Seoul (resuspended road dust and non-exhaust dust) was high. When the concentration of PM2.5 was high, the contribution of resuspended road dust was reduced due to an increase of secondary generating materials. Currently, data on emission reduction due to the COVID-19 cannot be assessed, which we believe will enable more accurate contribution calculations in the future. © 2021

Designing Medical Facilities to Care for Patients with Highly Hazardous Communicable Diseases

Certain highly hazardous communicable diseases (HHCD), including viral hemorrhagic fevers, the Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome virus (SARS), have caused nosocomial outbreaks in unprepared facilities. Consequently, biocontainment units have been constructed to protect caregivers, patients, and family members, in addition to providing optimal care of the infected patient. Biocontainment units have adopted many of the design features originally found in biocontainment laboratories and can serve as national referral facilities for the most severe and highly hazardous infections.Although a patient with a HHCD can show up at any healthcare facility unannounced, not every hospital can or should attempt to establish a biocontainment unit. Nevertheless, there are design features or management principles found in biocontainment units that can be adopted in most facilities. Awareness of the potential risk, in addition to adopting structural and policy control measures, can do a lot to prepare a facility for the next unexpected infectious disease outbreak. FAU - Kortepeter, Mark G.